Doctor's attempt to inject hospital superintendent with HIV+ blood

London, May 20: The current physical distancing guidelines of 6 feet may be insufficient to prevent COVID-19 transmission, according to a study which says a mild cough in low wind speeds can propel saliva droplets by as much as 18 feet.

Researchers, including those from the University of Nicosia in Cyprus, said a good baseline for studying the airborne transmission of viruses, like the one behind the COVID-19 pandemic, is a deeper understanding of how particles travel through the air when people cough.

In the study, published in the journal Physics of Fluids, they said even with a slight breeze of about four kilometres per hour (kph), saliva travels 18 feet in 5 seconds.

"The droplet cloud will affect both adults and children of different heights," said study co-author Dimitris Drikakis from the University of Nicosia.

According to the scientists, shorter adults and children could be at higher risk if they are located within the trajectory of the saliva droplets.

They said saliva is a complex fluid, which travels suspended in a bulk of surrounding air released by a cough, adding that many factors affect how saliva droplets travel in the air.

These factors, the study noted, include the size and number of droplets, how they interact with one another and the surrounding air as they disperse and evaporate, how heat and mass are transferred, and the humidity and temperature of the surrounding air.

In the study, the scientists created a computer simulation to examine the state of every saliva droplet moving through the air in front of a coughing person.

The model considered the effects of humidity, dispersion force, interactions of molecules of saliva and air, and how the droplets change from liquid to vapour and evaporate, along with a grid representing the space in front of a coughing person.

Each grid, the scientists said, holds information about variables like pressure, fluid velocity, temperature, droplet mass, and droplet position.

The study analysed the fates of nearly 1,008 simulated saliva droplets, and solved as many as 3.7 million equations.

"The purpose of the mathematical modelling and simulation is to take into account all the real coupling or interaction mechanisms that may take place between the main bulk fluid flow and the saliva droplets, and between the saliva droplets themselves," explained Talib Dbouk, another co-author of the study.

However, the researchers added that further studies are needed to determine the effect of ground surface temperature on the behaviour of saliva in air.

They also believe that indoor environments, especially ones with air conditioning, may significantly affect the particle movement through air.

This work is important since it concerns safety distance guidelines, and advances the understanding of the transmission of airborne diseases, Drikakis said.

New Delhi, Jun 24: Expanding the testing criterion for coronavirus, the Indian Council of Medical Research has said it should be made widely available to all symptomatic individuals across the country.

"Since test, track and treat' is the only way to prevent spread of infection and save lives, it is imperative that testing should be made widely available to all symptomatic individuals in every part of the country and contact tracing mechanisms for containment of infection are further strengthened," it said in an advisory on 'Newer Additional Strategies for COVID-19 Testing' on Tuesday.

In its revised testing strategy for COVID-19 issued on May 18, the Indian Council of Medical Research (ICMR) had advised testing for all symptomatic Influenza-like illness (ILI) among returnees and migrants within seven days of illness.

All hospitalised patients who develop ILI symptoms, symptomatic individuals living within hotspots or containment zones and healthcare and frontline workers involved in containment and mitigation of coronavirus were also advised testing.

The apex health research body has also advised authorities to enable all government and private hospitals, offices and public sector units to perform antibody-based COVID-19 testing for surveillance to help allay fears and anxiety of healthcare workers and office employees.

The earlier advisories on rapid antibody testing advisories had focused on areas reporting clusters (containment zones), large migration gatherings/evacuees centers and testing of symptomatic ILI individuals at facility level.

Besides, the ICMR on Tuesday also recommended deployment of rapid antigen detection tests for COVID-19 in combination with RT-PCR tests in all containment zones, all central and state government medical colleges and government hospitals, all private hospitals approved by the National Accreditation Board for Hospitals and Healthcare (NABH), all NABL-accredited and ICMR approved private labs, for COVID-19 testing.

All hospitals, laboratories and state governments intending to perform the point-of-care antigen tests need to register with ICMR to obtain the login credentials for data entry.

"ICMR advises all state governments, public and private institutions concerned to take required steps to scale up testing for COVID-19 by deploying combination of various tests as advised," the advisory added.

Tehran, Jan 12: Iranian police dispersed students chanting “radical” slogans during a Saturday gathering in Tehran to honour the 176 people killed when an Ukrainian airliner was mistakenly shot down, Fars news agency reported.

News agency correspondents said hundreds of students gathered early in the evening at Amir Kabir University, in downtown Tehran, to pay respects to those killed in the air disaster. The tribute later turned into an angry demonstration.

The students chanted slogans denouncing "liars" and demanded the resignation and prosecution of those responsible for downing the plane and allegedly covering up the accidental action.

Iran said Saturday that the Ukraine International Airlines Boeing 737 was “unintentionally” shot down on Wednesday shortly after taking off from Tehran's main airport. All 176 people on board died, mostly Iranians and Canadians, many of whom were students.

Fars, which is close to conservatives, said the protesting students chanted “destructive” and “radical” slogans. The news agency said some of the students tore down posters of Qasem Soleimani, the Iranian general killed on January 3 in a US drone strike on Baghdad.

Fars published pictures of demonstrators gathered around a ring of candles during the tribute and a picture of a torn poster bearing the image of a smiling Soleimani. It said that police "dispersed" them as they left the university and blocked streets, causing a traffic jam.

In an extremely unusual move, state television mentioned the protest, reporting that the students shouted "anti-regime" slogans.

A video purportedly of the protest circulated online showing police firing tear gas at protesters and a man getting up after apparently being hit in the leg by a projectile. It was not possible to verify the location of the video, or when it was filmed.

Iran's acknowledgement on Saturday that the plane had been shot down in error came after officials had for days categorically denied Western claims that it had been struck by a missile. The aerospace commander of Iran's Revolutionary Guards accepted full responsibility.

But Brigadier General Amirali Hajizadeh said the missile operator acted independently, shooting down the Boeing 737 after mistaking it for a "cruise missile".